1. Field of the Invention
This invention relates to a curable silicone composition. More particularly, it relates to a curable silicone composition useful as a release agent.
2. Description of the Prior Art
Silicone pressure-sensitive adhesives have good thermal resistance, cold resistance, chemical resistance and electrical insulating properties, and hence are used for extensive purposes.
As release agents used for release papers for protecting the adhesive surfaces of the silicone pressure-sensitive adhesives, it is known to use those mainly composed of a copolymer of a polyfluoroalkylvinyl monomer and a silicone monomer containing a vinyl group and a hydrolyzable group. Japanese Pre-examination Patent Publication (KOKAI) No. 228078/1986 discloses a method in which such a copolymer is cured to form a release layer.
The release layer obtained by the above method has release properties of practical utility to the silicone pressure-sensitive adhesives. Since, however, the copolymer has a low viscosity before cured, the copolymer has insufficient wettability for substrates such as papers, laminated papers and films and therefore is liable to be repelled when applied on the substrates. As a result, no satisfactory release layer can be formed on the part at which the copolymer has been repelled, thus causing various troubles. In the case of a substrate insufficiently sealed up such as glassine paper, the copolymer penetrates seriously through it, so that it is difficult to obtain a release paper with stable release properties. In particular, when the release agent diluted with a solvent is used, the above repellency or penetration is more seriously occur, bringing about a great problem from a practical viewpoint.